Spark plug



E B RILEY www M, 1924,

Filed June..9 l 1922 Patented duly l, 1.??

ELLSWORTH 1B. RILEY, 0F PHILADELPHIA, PENNSYLV t l SPK PLUG.

' Application mea June a,

To all w hom it may camera.'

Be it known that I, ELLswon'rH B. RILEY, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain new and useful Improvements lin Spark Plugs, of 'which the following is a speciication.

Une object of my invention is to provide an improved spark plug which can be used 10 in connection with internal combustion engines and to so construct said plug that parts thereof will prevent oil, soot and carbon from entering the chamber of the outer electrode and collecting on the inner wall therellt of; the construction also being such as to prevent said collection or deposit of oil, soot and carbon on the outer walls of the central electrode and its insulator.

Another object of my improved construc- 20 tion is to prevent the flame of the explosion from coming in contact with the central electrode insulator, thereby avoiding cracking or injury to the insulator.

A further object is to provide adequate 2W means which will shield the sparking surface o f the outer electrode; said means being preferably in the form of an upwardly flaring annularY skirt which will receive any surplus oil that might run down from the l 30 outer surface of the plug.

Another object of my linvention is to provide the lower sparking surface of the outer electrode with an annular portion Haring upward in cross section to correspond wit 35 the central electrode; the latter having a projection forming an annular raised spark crest insuring an adequate spark around the complete circle of the sparking gap.

Furthermore, l[ preferably make the lower t portion of the central electrode cone shape and of such size as to include a portion which extends outward beyond the sparking l.surface so as to prevent oil and other sub- .stances from being pumped to the interior t of the plugl during the operation of the engine.

rllhese objects, and other advantageous ends which will be described hereinafter,

l attain in the`following manner, reference 50 being had to the accompanying drawings in which- Figure 1 is an elevational View of a spark plug made in accordance with my invention,

Figure 2 is a'central longitud .al section 1922. Serial No. 567,142.

of said plug, the central electrode being an illustrated in outside elevation,

Figure 3 is an enlarged transverse section, taken on the line 3 3 of Figure 1,

Figure 4 is an enlarged transverse section taken on the line Ll--t of Figure 1, and

Figure 5 is a greatly enlarged fragmen--v tary sectional view of the lower portion of said plug.

Referring to the drawing, 6-represents an outer electrode made in the form of a hollow e5 metallic body portion. vThis body portion has anv externally screw threaded part 7 adapted to be screwed in a tapped openin .in an internal combustion engine in the usua manner of attaching spark plugs.

The body portion 6 includes a hollow downward extending skirt 8 which depends from the portion 7 The outer downwardly tapering surface 9 of the skirt 8 adjacent its bottom intercepts an annularly extending 75 upper ledge surface or shoulder 10; said ledge surface being produced by a peripheric flange 11 of the skirt 8.

The ledge surface 10 preferably flares upward at a slight angle to the horizontal for et a purpose hereinafter rendered obvious. The outer -surface 12 of the ange 11 tapers downwardly from the outer ed e 13 and terminates in an annular lower edge 14.

From the edge 14 the inner surface por- 85 tion 15 of the flange 11 tapers upwardly andpreferably intercepts an upwardly tapering annular surface portion 16 of the flange 11; said surface portion 16 prefer ably extending at a steeper angle to the horie0 zontal than does the surface portion 15.

A central electrode 17 includes a rod 18 which extends throu h the-body portion 6 and through an insu ator 19. In the form illustrated the insulator has an enlargement au 20 'which is held against a sledge 21 of the body portion by a gland nut 22 which is screwed into the top of the body portion 6. Also in the form illustrated the rod 18 of the central `electrode has an integral collar or toe enlargement 23 which abuts a lower shoulder 24 of the insulator 19. 'The upper end of the rod 18 is screw threaded and, at a vposition above the top end of the insulator, a nut 25 engages the screw threaded ortion not of the rod 18 and serves to secure t e central electrode 17 to the insulator.

A wire-binding nut 26 is mounted on the A and of the relative top of the rod 18 for the purpose of securing an electric conduit wire in connection with the central electrode; theouter electrode being electrically grounded on the engine in `the usual manner.

The lower end of the electrode rod has thereon a metallic terminal cap which flares upwardly, preferably from the bottom of the rod 18 toan annular edge 28, said edge being of greater diameter than the edge 14 of the flange 11. The -terminal cap 27 has an annular top surface portion 29 which extends inwardly from the edge 28 to an annular sparking crest flange 30.

This sparking crest -flange 30 extends above the level of the surface portion 29 and terminates in the annular edge 31 below the surface portion 16, said edge 31, in the form illustrated, being of smaller diameter than the edge 14 of the flange 11.

The crest flange 30 has an outer surface portion 32 which flares downward from the edge V31 slightly below the surface portion 15 of the flange 11, and this surface portion 32 preferably intercepts an annular downwardly flaring surface portion 33 of the crest flange 30. The surface portion 33 intercepts the surface 29, the lower portion of the surface 33 preferably being of greater diameter than the edge 14 of the flange 11.

The terminal cap' 27 can be secured to the lower end of the rod 18 in any suitable manner, such for example as by welding, forced fit, or brazing, ory ifdesired said cap can be made integral with the rod 18.

The space between the surface portions 15 and 32 forms an annular sparking gap and thus the sparks can occur throughout the entire areas of these surfaces and also between the edges 14 and 31.

In the use of my improved plug, any oil or products of combustion which strike the surface 9 of the skirt 11 will run down over said surface and collect on the ledge surface 10.

If said oil or products of combustion should be in such quantity. as to run over the edge 13 they will immediately shed downward onto the outer slanting surface of the crest flange 30 and surface 29 of the cap 27. Therefore the arrangement of parts is such that said oil and products of combustion will not engage the surface 32 or edge 31.

The cap 27, by being made frusto-conical proportions with respect to the flange 11 above set forth, will serve to prevent the ame of the combustion or the products of combustion from entering the lower opening of the skirtv 8, since the edge 28 is of such diameter as to serve as a guard to prevent the flame and products of combustion from directly passing 4through the opening of the body portion into the chamber thereof.

Furthermore, the electrode insulator will be protected against the direct fire of the combustion `and thus the lpossibilities of injury to the insulator are reduced to a minimum.

By the construction of parts as above set forth and as illustrated I have found in actual practice and use of the device that the sparking portions are kept practically free of any carbon or other deposit as are also the other portions contained within the body electrode.

While I have described nl v invention as faking a particular form, it will be understood that the various parts of my invention may be changed without departing from the spirit thereof, and hence I do not limit myself to the precise construction se(` forth, but consider that I am at liberty to make such changes and alterations as fairly come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. A spark plug including a depending electrode body providing an opening at its lower end; and an electrode having a cap provided witha sparking crest below said end of the body, said crest in cross section having its outer side slanting outwardly and downwardly, said outer side of the crest having its upper portion extending to a position closer to the longitudinal axis of the plug than is the lowest part of the wall of said opening whereby oil running down from said wall will drop onto said outer side of the crest.

2. A. spark plug having an electrode body, the lower part of said body having a downwardly slanting lower surface terminating in a lower edge; and a second electrode having a sparking crest with an outwardly and downwardly slanting surface directl opposed to and under said edge of the body. 3. A spark plug having an electrode body, the lower part of said body having a downwardly slanting lower surface terminating in' a lower edge; and a second electrode having a sparking crest with an outf wardly and downwardly slanting surface directly opposed to and under said edge of the body, said body having a surroundin oil collecting pocket above said edge, sai body having a surface leading from the overflow part of said pocket to said edge whereby any overflow oil running down said latter surface will fall on the outer side of said crest.

4. A spark plug having a depending electrode body with a part providing a lower opening; and a second electrode having a portion extending through said another portion spaced below said openin of greater diameter than said part of the e ectrode body, said second mentioned portion of said second electrode having a sparking opening and raeaeea Hange having a portion o smaller diameter than 'the lower art of said open n.

5. A spark p ug having a de en ing e1ectrode body with a part provi ing a lower opening; and a second electrode having a portion extending through said opening and another portion spacedbelow said opening of greater diameter than said partof the electrode body, said second mentioned portionA of said second electrode having a Sparking crest Hange below said opening, said crest dange having a portion of smaller diameter than the lower part of said opening, said second mentioned portion of the second electrode also having an upper surface portion projecting outside the contines of said sparking crest.

6. A spark plug having a depending electrode body portion including a lower edge providing an opening; and a second electrode having a portion in alignment with said o ening inc uding a flange providing a spar ing crest, said sparking crest flangeincludinga portion below said opening of smaller diameter than said lower edge of the body electrode.

7. A spark plug having a depending electrode-body portion including a lower edge providing an opening; and a second electrode having a portion in alignment with said opening including a flange providing a sparking crest, said sparking crest flange including a' portion below said opening of smaller diameter than said'lower ed e of the body electrode, said sparking crest ange having an outer portion of greater diameter than said edge ,of the body electrode.

8. A spark plug including' a depending electrode body providing an opening; and a central electrode having a cap below said opening provided with a sparking crest, said cap having a portion extending beyond said crest. y 1

9. A spark plug including a -depending electrode body having a sparking flange which in cross section tapers downwardly; and a central electrode having a cap with a sparking crest flan e below -said first flange, said crest flaring' downwardly in cross section.

In testimony whereof, l have signed my name to this specification, in the presence of two subscribing witnesses.

ELLSWURTH JB. RILEY.

Witnesses:

FREDK J, ll l l er." AUGUsTUe 1B.' Corrne.

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